JP2008236931A - Claw-pole type outer stator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a claw-pole type outer stator that can increase or downsize winding space. <P>SOLUTION: The outer stator is provided with a molded yoke 1, which has yokes 1aa-1bb formed by insert molding having pole teeth cut and made to stand from outer flange portions F<SB>1</SB>-F<SB>4</SB>and connected to each other in a back-to-back state with the pole tooth K<SB>1</SB>of an A-phase outer yoke 1aa and the pole tooth K<SB>2</SB>of an A-phase inner yoke 1ab in a non-contact engagement state and with the pole tooth K<SB>3</SB>of a B-phase inner yoke 1ba and the pole tooth K<SB>4</SB>of a B-phase outer yoke 1bb in a non-contact engagement state; A-phase coils 40a wound between the outer flange portions F<SB>1</SB>, F<SB>2</SB>; B-phase coils 40b wound between the outer flange portions F<SB>3</SB>, F<SB>4</SB>; a first casing 20, which covers one side of the molded yoke 1; and a second casing 30 which covers the other side of the molded yoke 1. An inside circumferential edge surface s<SB>1</SB>of the inner flange portion f<SB>1</SB>of the first casing 20 is joined to the outside circumferential edge surface S<SB>1</SB>of the outer flange portion F<SB>1</SB>, while an inside circumferential edge surface s<SB>2</SB>of the inner flange portion f<SB>2</SB>of the first casing 30 is joined to the outside circumferential edge surface S<SB>4</SB>of the outer flange portion F<SB>4</SB>. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stepping motor, and more particularly to its claw pole type outer stator.

A claw pole type outer stator used for a stepping motor is composed of a mold yoke, first and second phase coils, a case and a cover plate as disclosed in Japanese Patent Laid-Open No. 10-94236. The mold yoke is formed by insert-molding four yokes having a plurality of pole teeth (claw poles) standing on the inner peripheral edge of the annular outer collar portion and arranged in an annular row, and the pole teeth of the first yoke and the poles of the second yoke The teeth are connected in a non-contact meshing state, the pole teeth of the third yoke and the pole teeth of the fourth yoke are connected in a non-contact meshing state, and the annular outer flange portion of the second yoke and the third yoke Are connected to each other in a back-to-back state. The first phase coil is wound between the annular outer flange portion of the first yoke and the annular outer flange portion of the second yoke, and the second phase coil is an annular outer flange portion of the third yoke and an annular shape of the fourth yoke. Wrapped between outer casings. The case covers the bottom yoke of the annular yoke of the fourth yoke to house the mold yoke, and the cover plate covers the annular outer casing of the first yoke to block the opening of the case.
JP-A-10-94236 (FIG. 14)

  Although this mold yoke has the advantage that an insulating resin layer can be simultaneously formed on the outer peripheral surface of the pole teeth and the inner side surface of the annular outer casing during the insert molding, the thickness of the insulating resin layer is at least 150 to The thickness becomes 200 μm, and the winding space (number of turns) decreases accordingly.

  In view of the above problems, an object of the present invention is to provide a claw pole type outer stator capable of increasing the winding space or reducing the size.

  In order to solve the above problems, a claw pole type outer stator according to the present invention insert-molds four yokes having a plurality of pole teeth standing on the inner peripheral side of the annular outer flange portion and arranged in an annular row. The pole teeth of the first yoke and the pole teeth of the second yoke are connected in a non-contacting engagement state, and the pole teeth of the third yoke and the pole teeth of the fourth yoke are connected in a non-contact engagement state. Between the annular outer flange portion of the third yoke and the annular outer flange portion of the third yoke in a back-to-back state, and between the annular outer flange portion of the first yoke and the annular outer flange portion of the second yoke. The first phase coil, the second phase coil wound between the annular outer flange portion of the third yoke and the annular outer flange portion of the fourth yoke, and the cylindrical portion of the annular outer flange portion of the second yoke. A first case that joins the inner ends and covers one side in the axial direction of the mold yoke, and a cylindrical portion on the annular outer flange portion of the third yoke A second case that joins the ends and covers the other axial side of the mold yoke, and an inner peripheral surface of the outer end side inner flange portion of the first case on an outer peripheral surface of the annular outer flange portion of the first yoke And the inner peripheral surface of the outer end side inner flange portion of the second case is bonded to the outer peripheral surface of the annular outer flange portion of the fourth yoke.

  In such a configuration, since the inner peripheral surface of the outer end side inner flange portion of the first case is joined to the outer peripheral surface of the annular outer flange portion of the first yoke, the outer end side inner flange portion of the first case. The axial length of the outer stator can be shortened by the thickness of the outer stator, and the inner peripheral surface of the outer end side inner flange portion of the second case is also joined to the outer peripheral surface of the annular outer flange portion of the fourth yoke. The axial length of the outer stator can be shortened by the thickness of the outer end side inner flange portion of the second case, and the distance between the annular outer flange portion of the first yoke and the annular outer flange portion of the second yoke accordingly. In addition, the winding space can be increased by extending the distance between the annular outer flange portion of the third yoke and the annular outer flange portion of the fourth yoke. Conversely, since the axial length of the outer stator can be shortened by twice the plate thickness of the annular outer flange portion, the size can be reduced.

  In joining within the plate thickness of the inner peripheral surface of the outer end side inner flange portion of the case and the outer peripheral surface of the annular outer flange portion of the yoke, the inner peripheral surface is orthogonal to the outer surface of the outer end side inner flange portion. In addition, the outer peripheral surface of the annular outer flange portion may be joined to the outer peripheral surface at right angles, but in order to secure the bonding area, the outer peripheral surface of the annular outer flange portion of the first and fourth yokes has a diameter. As the diameter increases outward in the direction, the inner surface of the inner flange portion of the outer end side of the first and second cases is an inversely tapered surface joined to the tapered surface. desirable. In this case, the inner peripheral surface of the outer end side inner flange portion of the first and second cases also functions as a guide when the first and second cases are attached to the mold yoke.

  In addition, the annular outer flange portion of the first yoke and the outer end side inner flange portion of the first case have a first detent engagement portion, and the annular outer flange portion of the fourth yoke and the outer end of the second case. It is desirable to have a second anti-rotation engaging portion on the side inner flange portion. When the first and second cases are put on the mold yoke and assembled, positioning can be performed by the anti-rotation engaging portion. The anti-rotation engaging portion may be, for example, a notch portion formed in one of the annular outer flange portion and the outer end side inner flange portion and a protruding piece formed in the other direction.

  Further, the inner peripheral edge sides of the outer end side inner flange portions of the first and second cases are respectively polygonal, and the outer peripheral edge sides of the annular outer flange portions of the first to fourth yokes are fitted into the inner peripheral edge side. It is also good. There is no need to form the anti-rotation engaging portion as described above. In this case, each yoke is preferably provided with pole teeth on the inner side corresponding to one or every other vertex of the polygonal vertex. The area of the portion having the pole teeth in the annular outer flange portion is not reduced, and the strength of the yoke can be maintained.

  The claw pole type outer stator is preferably used for a stepping motor.

  The present invention can provide a claw pole type outer stator capable of increasing the winding space or downsizing.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.
Example 1
1A is a longitudinal front view showing an outer stator for a stepping motor according to Embodiment 1 of the present invention, FIG. 1B is a plan view thereof, and FIG. 2A is a plane showing a yoke used for the outer stator. FIG. 2B is a front view of the yoke.

This outer stator for a stepping motor has a mold yoke 1 that is inserted into a first case 20 and a second case 30 made of magnetic material and into which a rotor magnet (not shown) is inserted. As shown in FIG. 2, each of the yokes 1aa to 1bb having the same shape has five pole teeth (claw poles) K that are cut and raised substantially at right angles at the inner peripheral edges of the annular outer flanges F _{1 to} F ₄ and arranged in an annular shape. with a ₁ ~K _4.

Mold yoke 1 by insert molding, staggered through an insulating resin _{M 1} and pole teeth _{K 2} of A Aisoto yoke (first yoke) 1aa pole teeth _{K 1} and A Aiuchi yoke (second yoke) 1ab connected by engagement state, B Aiuchi York (third yoke) 1ba pole teeth _{K 3} and B Aisoto York (4th yoke) 1bb the pole teeth _{K 4} of alternately through the insulating resin _{M 2} Using the insulating resins M ₁ and M ₂ in a back-to-back state, the annular outer flange portion F _{2 of} the A-phase inner yoke 1ab and the annular outer flange portion F _{3 of the} B-phase inner yoke 1ba are connected in mesh. It is a connected unitary product.

A phase coil 40a in the annular hollow portion between the annular outer flange portion _{F 2} of the annular outer flange portion _{F 1} and A intra-phase yoke 1ab of A Aisoto yoke 1aa is wound, the B Aiuchi yoke 1ba B-phase coil 40b in the annular hollow portion between the annular outer flange portion F ₃ and B Aisoto annular outer flange portion F ₄ of the yoke 1bb is wound. Here, the outer peripheral surfaces of the pole teeth K ₁ , K ₂ and the inner surfaces of the annular outer flange portions F ₁ , F ₂ are covered with an insulating resin M ₁ , and the outer peripheral surfaces and circles of the pole teeth K ₃ , K _4. The inner surfaces of the annular outer flange portions F ₃ and F ₄ are covered with an insulating resin M ₂ .

A terminal block 3 of insulating resin is formed at one place on the outer peripheral side of the ring-shaped outer casing portions F ₂ and F _{3 in} a back-to-back state, and a terminal pin T ₁ for tying both ends of the coil winding to this terminal block 3 ~T ₄ are implanted.

The first case 20 has a cylindrical portion 21 and an annular inner flange portion f ₁ bent radially inward at the outer end, and an outer peripheral surface S _{1 of the} annular outer flange portion F ₁ of the first yoke 1aa. the circular annular flange portion inner peripheral surface s ₁ and is bonded to f _1, and the outer surface of the circular annular flange portion f ₁ of the outer surface and the annular outer flange portion F ₁ is in the flat and. The inner peripheral surface s ₁ is orthogonal to the outer surface of the annular inner flange portion f ₁ , and the outer peripheral surface S ₁ is orthogonal to the outer surface of the annular outer flange portion F ₁ . The second casing 30 has an annular inside flange portion f ₂ by bending at the outer end and the cylindrical portion 31 radially inwardly, the outer peripheral edge surface of the annular outer flange portion F ₄ of the fourth yoke 1bb S ₄ and the inner peripheral surface s ₂ and is bonded to the annular inside flange portion f _2, and the outer surface of the circular annular flange portion f ₂ of the outer surface and the annular outer flange portion F ₄ becomes flat. Inner peripheral surface s ₂ are orthogonal with respect to the outer surface of the circular annular flange portion f _2, the outer peripheral edge surface S ₄ is orthogonal to the outer surface of the annular outer flange portion F _4.

A notch E is formed in a portion corresponding to one pole tooth K ₁ , K ₄ of the outer peripheral edges of the annular outer flanges F ₁ , F ₄ of the A-phase outer yoke 1aa and the B-phase outer yoke 1bb. In addition, an engagement protrusion P that fits into the notch E is formed on the annular inner flanges f ₁ and f ₂ of the first and second cases 20 and 30.

In this example, the annular inner flanges f ₁ and f ₂ of the first and second cases 20 and 30 are the annular outer flanges F ₁ and F _{4 of the} A-phase and B-phase outer yokes 1aa and 1bb as in the prior art. The inner peripheral edge surfaces s ₁ and s _{2 of the} annular inner flange portions f ₁ and f ₂ are not overlapped with the outer peripheral edge surfaces S ₁ and S ₄ of the annular outer flange portions F ₁ and F ₄ . Therefore, the axial length of the outer stator can be shortened by the thickness of the annular inner flanges f ₁ and f ₂ . Therefore, A Aisoto yoke 1aa annular outer flange portion _{F 1} and the A intra-phase annular outer flange portion _{F 3} of the distance and B intra-phase yoke 1ba of the annular outer flange portion _{F 2} of the yoke 1ab B phase to extend the distance between the annular outer flange portion F ₄ of the outer yoke 1bb can increase the winding space, it is possible to high torque. On the contrary, the axial length of the outer stator can be shortened by an amount equivalent to twice the plate thickness of the annular outer flange portions f ₁ and f ₂ , and the size can be reduced.

A cutout portion E is formed in the annular outer flange portions F ₁ and F ₄ of the A-phase and B-phase outer yokes 1aa and 1bb, and the annular inner flange portions f ₁ and f _{1 of} the first and second cases 20 and 30 are formed. since the engaging protrusion P of the f ₂ fits into the cutout portion E is formed, when assembling is covered with a first and a second casing 20 and 30 to mold the yoke 1 functions as rotation prevention engaging portion The positioning at the time of attachment becomes easy.

(Example 2)
3A is a longitudinal front view showing an outer stator for a stepping motor according to a second embodiment of the present invention, FIG. 3B is a plan view thereof, and FIG. 4A is a plane showing a yoke used for the outer stator. FIG. 4B is a front view of the yoke. 3 and 4, the same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted.

In the first embodiment differs from the embodiment, the yoke 1aa~1bb the outer peripheral edge has a positive decagonal profiled annular outer flange portion _F 1 'to F _4', the first and second case Correspondingly Nos. 20 and 30 are provided with deformed annular inner flanges f ₁ ′ and f ₂ ′ whose inner peripheral edge is a regular decagon. For this reason, it is not necessary to provide a special anti-rotation engaging portion. Further, the yokes 1aa~1bb is inwardly corresponding to every vertex of the regular decagonal apex provided with pole teeth _K 1 ~K _4. For this reason, the area of the portion having the pole teeth K _{1 to} K _{4 in} the deformed annular outer flange portions F ₁ ′ to F ₄ ′ is not reduced, and the strength of the yokes 1 aa to 1 bb can be maintained during insert molding.

(Example 3)
5A is a longitudinal front view showing an outer stator for a stepping motor according to Embodiment 3 of the present invention, FIG. 5B is a plan view thereof, and FIG. 6A is a plane showing a yoke used for the outer stator. FIG. 6 and FIG. 6B are front views of the yoke. 5 and 6, the same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted.

In this example, the difference from Example 1 is that the outer peripheral edge surfaces S ₁ ′ and S ₄ ′ of the annular outer flanges F ₁ and F ₄ of the A-phase and B-phase outer yokes 1aa and 1bb are respectively radially outward. As the diameter increases, the inner surface s ₁ ′, s ₂ ′ of the annular inner flanges f ₁ , f ₂ of the first and second cases 20, 30 is respectively tapered. The tapered surface is a reverse tapered surface joined to the outer peripheral surfaces S ₁ ′ and S ₄ ′. For this reason, in addition to ensuring a bonding area, it also functions as a guide when the first and second cases 20 and 30 are put on the mold yoke 1 and assembled.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal front view which shows the outer stator for stepping motors which concerns on Example 1 of this invention, (B) is the top view. (A) is a top view which shows the yoke used for the outer stator, (B) is a front view of the yoke. The longitudinal section front view which shows the outer stator for stepping motors concerning Example 2 of the present invention, (B) is the top view. (A) is a top view which shows the yoke used for the outer stator, (B) is a front view of the yoke. The longitudinal section front view which shows the outer stator for stepping motors which concerns on Example 3 of this invention, (B) is the top view. (A) is a top view which shows the yoke used for the outer stator, (B) is a front view of the yoke.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mold yoke 1aa ... A phase outer yoke (1st yoke)
1ab ... A phase inner yoke (second yoke)
1ba ... B phase inner yoke (third yoke)
1bb ... B phase outer yoke (fourth yoke)
3 ... terminal block 20 ... first case 21, 31 ... tubular portion 30 ... second case 40a ... A phase coil 40b ... B-phase coil E ... cutout portion _F 1 to F 4 _... annular outer flange portion _F 1 ' ~F ₄ '... irregular-shaped outer annular flange portion _{f 1, f} 2 _... circle annular flange portion _f 1', _{f 2} '... irregular-shaped annular flange portion _K 1 ~K 4 _... pole teeth (claw pole)
M ₁ , M ₂ ... insulating resin P ... engaging protrusions S ₁ , S ₄ , S ₁ ', S ₄ ' ... outer peripheral surface s ₁ , s ₂ , s ₁ ', s ₂ ' ... inner peripheral surface T ₁ ~T 4 _... terminal pin

Claims (6)

Four yokes having a plurality of pole teeth standing on the inner peripheral side of the annular outer flange portion and arranged in an annular row are insert-molded so that the pole teeth of the first yoke and the pole teeth of the second yoke are in non-contact engagement. And the third yoke pole teeth and the fourth yoke pole teeth are connected in a non-contacting state, and the second yoke annular outer flange portion and the third yoke annular outer flange portion are connected to each other. A mold yoke connected in a mated state, a first phase coil wound between an annular outer flange portion of the first yoke and an annular outer flange portion of the second yoke, and an annular outer surface of the third yoke A second phase coil wound between a flange portion and an annular outer flange portion of the fourth yoke, and an inner end of a cylindrical portion joined to the annular outer flange portion of the second yoke, the shaft of the mold yoke A first case that covers one side in the direction, and an inner end of the cylindrical portion joined to the annular outer flange portion of the third yoke, A claw pole outer stator and a second case covering a direction other side,
The inner peripheral surface of the outer end side inner flange portion of the first case is joined to the outer peripheral surface of the annular outer flange portion of the first yoke, and the second outer periphery surface of the annular outer flange portion of the fourth yoke is joined to the second outer peripheral surface. A claw pole type outer stator characterized in that the inner peripheral surface of the inner flange portion of the outer end side of the case is joined. 2. The claw pole type outer stator according to claim 1, wherein the outer peripheral edge surfaces of the annular outer flange portions of the first and fourth yokes are tapered toward the inner side in the axial direction as the diameter increases radially outward. The claw pole type outer stator, wherein the inner peripheral edge surfaces of the outer end side inner flange portions of the first and second cases are respectively reverse tapered surfaces joined to the tapered surfaces. The claw pole type outer stator according to claim 1 or 2, wherein a first detent engagement portion is provided on the annular outer flange portion of the first yoke and the outer end side inner flange portion of the first case. A claw pole type outer stator having a second anti-rotation engaging portion on the annular outer flange portion of the fourth yoke and the outer end side inner flange portion of the second case. The claw pole type outer stator according to any one of claims 1 to 3, wherein inner peripheral side edges of outer end side inner flange portions of the first and second cases are polygonal, The claw pole type outer stator, wherein the outer peripheral side edge of the annular outer flange portion of each of the first to fourth yokes is a polygon fitted to the inner peripheral side edge. 5. The claw pole outer stator according to claim 4, wherein each of the yokes is provided with the pole teeth on the inner side corresponding to one or a plurality of vertices of the polygon. Shape outer stator. A stepping motor comprising a claw pole type outer stator as defined in any one of claims 1 to 5.

Images